How To: Install Roof Flashing

Install roof flashing in a stepped fashion, with overlapping sheets of aluminum, for effective and long-lasting protection from the elements.

Flashing is a good way of preventing water from entering a dwelling at the point where the roof meets the walls. To begin the installation, fold a five-by-seven piece of aluminum flashing lengthwise. Start at the bottom and work up, nailing high on the side wall and interweaving the flashing with the roof shingles. Overlap the pieces of flashing and repeat this process all the way up.